Once upon a time Ame was really impressed with the community's collective ability to solve puzzles, so as a social experiment Ame put a random tile with some instructions on it in a random place and said the first person to find that tile gets a free Dratini. She was interested in seeing if, in so many players, anyone would find something so arbitrary. Many looked, but none were able to find it.
As of right now, I'm rescinding that offer. Dratini will be technically in the game as of E13 so it no longer makes sense to keep this event around. For the curious, here's where it was.
PS just because something's in the game doesn't mean it's obtainable.